The goal of many surgical procedures is to remove, and/or remove so as to shape, body tissue at the site at which the procedure is performed. Surgery on the nasal and sinus cavities and/or the throat frequently involves performing this type of selective removal of tissue. For example, sinus surgery often involves the removal of diseased membranes and/or bone partitions and/or malformed portions of the sinus tissue, sometimes referred to as the sinus layer, and any boney material entrained in this layer. It is also often necessary to remove and/or selectively shape both hard and soft tissue that is part of the nasal system for both rhinoplasty procedures and for aesthetic procedures.
A number of instruments and surgical techniques have been developed to facilitate the performance of these surgical procedures. For example, the Applicant's Assignee manufactures a line of surgical tools under the trademark HUMMER that are especially designed to perform nasal, sinus and throat surgery. This line of tools includes a handpiece with an electrically driven motor. Different cutting accessories are designed to selectively fit the handpiece. Each cutting accessory typically has a hollow rotating or reciprocating shaft that is housed in a fixed tube-like outer housing. Irrigating solution is flowed to the distal end of the cutting accessory, the end applied to the surgical site, through an annular space between the moving shaft and the complementary outer housing. Substantially all, if not all, of this fluid is then drawn away from the distal end of the outer housing before it can be discharged from the cutting accessory by a suction that is applied through the rotating or reciprocating shaft. This fluid thus serves as transport media that flushes debris proximally, away from the patient.
Unfortunately, there are some disadvantages associated with the known methods of performing surgery on nasal, sinus or throat tissue. One of these disadvantages is associated with the fact that it is sometimes difficult to cleanly sever the tissue being worked on from the surgical site. This may be due, in part, to the fact that the suction force applied to the surgical site draws the tissue into the cutting accessory. Moreover, the tissue edges are prone to being pinched by the cutting accessory. This pinching can result in even the most skilled surgeon removing more tissue from the surgical site than is necessary to accomplish the desired result. This excess tissue removal can cause unwanted results. For example, during sinus surgery, this pinching can result in large sections of the sinus lining, not just the targeted section, being removed from the surgical site. This can result in unnecessary exposure of bone. Once the tissue lining is removed, the body then generates a new lining. The body's having to generate this new tissue can both delay the complete healing and increase the healing burden on the patient. Further, this new tissue is not as efficient as the lining it replaces.
Another difficulty with known (ear, nose and throat) surgical techniques is associated with the endoscopes that are often used to perform the surgical procedures. An endoscope is an elongated tube that is directed to the surgical site that is capable of transmitting light to and from the site. When the surgical site is at a difficult to reach or view location inside the patient, the surgeon will use the endoscope in order to view the site. An advantage of performing a surgery endoscopically is that it limits the extent to which the patient's body has to be open to the environment in order to gain access to the surgical site. This minimal opening of the patient's body both lessens the extent to which the body is open to infection during surgery and the extent to which it must heal after surgery.
Problems can arise when ENT surgery is performed endoscopically because, as a consequence of performing a surgical procedure, opaque solids and liquids present at the surgical site adhere to the distal end of the endoscope. This material obstructs the view of the surgical site. Presently, there are two ways to remove this material. One can remove the endoscope from the surgical site and wipe off the material that caused the obstruction. This involves withdrawing the endoscope, wiping off the obstructing material and then repositioning it at the surgical site. Moreover, as part of this process, an anti-fogging material applied to the endoscope is removed with the obstruction. This material then needs to be reapplied. Requiring each of these steps to be performed each time the endoscope becomes obstructed adds to the overall time it takes to perform a surgical procedure. This runs contrary to a goal of modern surgery to perform the procedure as quickly as possible in order to keep the time the patient is held under anesthesia as short as possible.
The second means of removing an obstruction is to provide some sort of fluid-dispersing device at the surgical site. Sometimes this device is a stand alone unit. Providing this device requires one to position this device in the vicinity of the surgical site. The presence of this device therefore adds to the number of devices that are positioned at the surgical site. Alternatively, the fluid delivery device is a sheath in which the endoscope is seated. Space between the inner wall of the sheath and the endoscope functions as a conduit through which fluid is delivered. A disadvantage of this arrangement is that it causes the overall diameter of the inserted, distal end portion of the endoscope to appreciably increase. The increase in size of this assembly results in a like increase in the difficulty of inserting the endoscope in position and maneuvering the endoscope.
One technique that has been tried to minimize the above problems associated with ENT surgery, including sinus surgery, is to flood the site at which the procedure is performed with irrigating solution. When other surgical procedures are performed, for example, endoscopic orthopedic surgery, sometimes referred to as arthroscopic surgery, this pool of fluid helps keep debris from adhering to the distal end of the endoscope.
However, when one performs arthroscopic surgery, the fluid is introduced into a substantially closed capsule in a limb. The nose, sinus and throat are different. The passages integral with these organs lead to the lungs. Thus, the flooding of these organs can lead to fluid flowing to other organs that are not intended to receive massive amounts of liquid, especially when a patient is under anesthesia.
Thus, when one tries to flood the nasal cavities, sinuses or throat prior to the actual performance of the surgical procedure, care must be taken to ensure that the solution does not flow to organs in which, if it were allowed to collect, it could potentially harm the patient. Consequently, given the extra steps and care that must be taken when one attempts to immerse a nasal passage or the throat in an irrigating solution in order to perform surgery on the adjacent tissue, it has not proven an especially popular surgical practice in ENT surgery.